Structural improvement for canned motor-pump

ABSTRACT

The invention is to provide a structural improvement for canned motor-pump, which has an outer shell arranged at the outside of a stator of the motor, an inner shell arranged inside the stator to pack a coil, an axis connected to impeller and bearing seats arranged at two sides of the axis to support the axis; its characteristics are that the upper edge or bottom edge of the inner shell has bending structure, which is to form at least two grooves surrounding the inner shell, and the openings of adjacent grooves are respectively faced the inside and outside of the inner shell, and washers are arranged inside the grooves; the inner shell is placed in the outer shell, and the bending structure and washer may be tightly abutted against the outer shell when the bearing seat is secured to the outer shell and, applying such multiple sealing structure may indeed block liquid from penetrating into the coil or stator arranged between the inner shell and outer shell.

FIELD OF THE INVENTION

The invention relates to a structural improvement for canned motor-pump, particularly to a canned motor-pump, upper edge or bottom edge of the inner shell of which is arranged bending structure, washers in which are arranged.

BACKGROUND OF THE INVENTION

Canned motor is usually provided for being arranged above pump, particularly, the sinking pump applied in the transportation of clean water, hot water and dirty water. Since the application of sinking pump is to sink the pump into liquid and contact therewith, so the shell of motor is designed as sealing can, such that the liquid is separated from the coil to prevent liquid from penetrating into coil. The traditional way to separate coil from liquid for a canned motor is to adopt a barrel sealing can, made of metal sheet, placed inside the stator of motor. Several prior structures are exemplified as follows.

As shown in FIG. 1, which is a “Diving Motor with Automatic Lubrication” (U.S. Pat. No. 5,898,245), wherein a motor 10 is to weld a barrel sealing can 18 a and two flanges 13, 14 at two sides of outer shell 12 of the stator 18 of the motor into one body; an axis 11 is supported between two upper and lower bearings 15, 16, which are secured by flanges 17, 19 located at two sides of the stator 18. Since this prior structure has the advantages of excellent rigidity and waterproof, so it is mostly applied in deep-well pump-motor or canned motor used in industrial process. However, its biggest drawback is that the whole set of motor must change when its barrel sealing can 18 a welded on the outer shell 12 is out of order, and it is impossible to change or dismantle the sealing can; furthermore, after the motor is running, the sealing can 18 a will be inflated and deformed because of the heat generated by eddy current, such that a wearing-out or crack will be occurred because of the inter-friction between the rotor 111 and the sealing can 18 a; even, the rotor 111 is stuck to make the coil 112 burned.

Please again refer to FIG. 2, which is a “Centrifugal Pump Driven by Diving Motor” (U.S. Pat. No. 6,140,725). The prior structure discloses a motor 1, of which rotor 5 is arranged in a sealing can 4, which is welded to upper and lower sides of a shell 2, and bearings 7, 8 are arranged in the sealing can 4. This structure has the same drawback as that of FIG. 1: the whole set of motor must change when the barrel sealing can 4 welded above the shell 2 according to this prior art is broken down, and it is impossible to change or dismantle the sealing can 4; in the meantime, since the function of the sealing can 4 is to support the bearings 7, 8, so the material and strength of the sealing can 4 must be enforced, such that the cost of material or process is raised; furthermore, after the motor is running, the sealing can 4 will be inflated and deformed because of the heat generated by eddy current, such that a wearing-out or break will be occurred because of the inter-friction between the rotor 5 and the sealing can 4; even, the rotor 5 is stuck to make the coil 3 burned.

Please further refer to FIG. 3, which shows an “Electric Motor” (U.S. Pat. No. 6,091,174). The motor 20 discloses an interchangeable structure of sealing can: the rotor 23 is arranged in the shell 24, and the coil 21 and stator 22 are arranged outside the shell 24, and the shell 24 is placed in the outer shell 25 and, cooperating with another shell 26, rubber washers 27 may be arranged among shells 24, 26 and outer shell 25, such that a sealing canned structure is constructed. The advantage of this prior art is the detachability of its shells 24, 26, and the rubber washer 27 may provide appropriate elasticity to make shells 24, 26 have enough space for hot expansion and cold constriction, such that it is possible to improve the drawback of deformation caused by the heat of eddy current in the prior sealing can sealed by welding method. However, the sealing ability of the arrangement of only one rubber washer 27 is still not good enough because, if the dimensional cooperation between the shells 24, 26 and outer shell 25 is inappropriate or the rubber washers 27 lose elasticity or generate cracks because of the long press and the contact with liquid, then the liquid will penetrate into the coil 21; moreover, since the function of the sealing can 24 is to support the bearing 28, so the material and strength of the sealing can 24 must be enforced, such that the cost of material or process is raised.

To enhance the sealing ability of aforementioned interchangeable canned motor, other leakage-resistant washers may be additionally arranged at appropriate positions of the shells. However, they still can not solve the problem substantially, and it is also impossible to overcome the material problem of rubber washer, especially it is impossible to reach the requirement of high leakage-resistance of a deep-water sinking pump.

SUMMARY OF THE INVENTION

According to the drawbacks of prior arts, the main objective of the present invention is to provide a structural improvement for canned motor-pump, and the bending structure and washers are applied to form a multi-sealing effect to further improve its sealing effect.

The secondary objective of the present invention is to provide a structural improvement for canned motor-pump, which is simply structured and easily processed, such that it is possible to reduce cost.

Another objective of the present invention is to provide a structural improvement for canned motor-pump, of which inner shell has detachability for facilitating maintenance.

Further another objective of the present invention is to provide a structural improvement for canned motor-pump, of which bearing seat is arranged on an outer shell with thicker wall, such that the damage of inner shell structure may be avoided and the fixation is ensured.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a structural cross-sectional view of a canned motor according to prior arts.

FIG. 2 is a structural cross-sectional view of a canned motor according to another prior arts.

FIG. 3 is a structural cross-sectional view of a canned motor according to further another prior arts.

FIG. 4 is a structural cross-sectional view of present invention.

FIG. 5A is a partial enlarging view of part A of FIG. 4.

FIG. 5B is a cross-sectional view of the liquid routes of the invention.

FIG. 6 and FIG. 7 are another two preferable embodiments according to the invention.

DETAILED DESCRIPTION OF THE INVENTION

For your esteemed member of reviewing committee to further recognize and understand the characteristics, objectives, and functions of the present invention, a detailed description together with corresponding drawings are presented thereinafter.

First, please refer to FIG. 4, which is a structural improvement for canned motor-pump according to the invention, which mainly includes an outer shell 30 made of metal material and an inner shell 40, which is arranged in the outer shell 30, and in which an axis 50 and a motor rotor 51 are arranged. A stator 52 and coils 53 are arranged between the outer shell 40 and the inner shell 30. The outer shell 30 has a thicker wall for providing a stronger structure to the motor. The inner shell 40 is made of metal sheet. Two bearings 54, 55 are arranged at two sides of the axis 50. The bearing 54 arranged above may be a plane bearing. The bearing 55 arranged below may be a plane bearing or a push-resistant bearing. Both bearings 54, 55 are arranged in two bearing seats 56, 57 respectively. The bearing seat 56 arranged above is projected appropriately out the outer shell 30. The projection section 561 is fastened by a fastening ring 562 to position the bearing seat 56 at the upper portion of the outer shell 30. The bearing seat 57 arranged below is arranged axially at the bottom in the inner shell 40. The bottom of the inner shell 40 is welded on a seat 58, which provides the needed position function and structure strength to the bearing seat 57, inner shell 40 and outer shell 30 simultaneously. Bolts 61 are applied to bolt the outer shell 30 to the pump shell 60. A sealing washer 581 is applied to insulate the liquid from penetrating into the coil 53 or stator 52. An axis 50 is extended into the pump shell 60 and is arranged axially to the impeller 62. Consequently, a canned motor-pump structure is constructed.

In the meantime, please refer to FIG. 4, FIG. 5A and FIG. 5B. Another characteristic of the invention is to provide the inner shell 40 with a bending structure 70 that is formed integrally by stamping method. In this embodiment, the bending structure 70 is arranged at the upper edge of the inner shell 40, wherein at least two grooves 71, 72 surrounding the inner shell 30. The opening directions of adjacent grooves 71, 72 are different. The groove 71 located inside the inner shell 40 is recessed from the outer surface of the inner shell 40 into the inner shell 40; that is, the opening of the groove 71 is faced outwardly. The adjacent groove 72 is recessed from the inner surface of the inner shell 40 to the outside of the inner shell 40; that is, the opening of the grove is faced inwardly. Two washers 73 a, 73 b are arranged in the two grooves 71, 72. To accommodate the grooves 71, 72 and the washers 73 a, 73 b, recessions may be arranged at the places corresponding to the bearing seat 56 or outer shell 30. As shown in the drawings, a recession 563 is arranged in the bearing seat 56 to accommodate the bending structure 70 and the washers 73 a, 73 b. After the inner shell 40 and the bearing 56 are pushed upwardly into the outer shell 30, the bending structure 70, the washers 73 a, 73 b and inner shell 40 are tightly arranged between the bearing seat 56 and the outer shell 30. The outer wall 711 of the groove 71 inside the inner shell 40 is abutted with the bearing seat 56. The washer 73 a arranged in the groove 71 is abutted between the inner wall 712 of the groove 71 and the outer shell 30. The outer wall 721 of the groove 72 located outside the inner shell 30 is abutted with the outer shell 30. The washer 73 b in the groove 72 arranged outside is in the meanwhile abutted among the inner wall 722 of the outside groove 72, the bearing seat 56 and outer shell 30. By the compact inter-abutments among bearing seat 56, the grooves 71, 72, the washers 73 a, 73 b and outer shell 30, a multi-sealing effect is constructed, such that the penetration of liquid into the route may be blocked out indeed. As shown in FIG. 5B, the arrows illustrate the penetration routes of liquid (in the drawings, the distances between each element are enlarged intentionally, such that the routes may be shown clearly). First, the liquid penetrates into the adjacency of the bearing seat 56 and the inner shell 40 or into the adjacency of bearing seat 56 and outer shell 30. Then, the penetrating fluid flows through the grooves 71, 72, the washers 73 a, 73 b and the outer shell 30. Through the adjacency of the inner shell 40 and the outer shell 30, the fluid penetrates into the coil (not shown in the drawings, please refer to FIG. 4) arranged between the inner shell 40 and the outer shell 30. When the bearing seat 56, the grooves 71, 72, the washers 73 a, 73 b and outer shell 30 are tightly abutted together and there is no gap left (as shown in FIG. 5A), the multiple blocking structure constructed by the bending structure 70 and the washers 73 a, 73 b according to the invention may indeed reach a superior effect to stop the liquid from invading into the coil if comparing to the prior art shown in FIG. 3, where only one washer 27 is arranged.

Another point needed to emphasize is that the inner shell 40, bearing seat 56 and outer shell 30 are all made of metal materials. The inner shell 40 is commonly made of metal sheet, of which thickness is approximately 0.2-0.3 mm. When the washers 73 a, 73 b press the grooves 71, 72 for inter-abutting with the bearing seat 56 and the outer shell 30, the interactions between metals will make the grooves 71, 72, the bearing seat 56 and the outer shell 30 pressed together naturally, such that a sealing effect may be reached.

Again, please refer to FIG. 6. A bending structure 70, same as that of FIG. 4, is arranged at the upper edge of the inner shell 40. The bending structure 70 includes two grooves, of which openings are faced to two different directions. There are two washers 73 a, 73 b arranged in the grooves 71, 72. A bending structure 170 is further arranged at the bottom edge of the inner shell 40. The structure of the bending structure 170 and the aforementioned bending structure 70 located at the upper edge of the inner shell 40 are related as mirror-reflecting state with respect to the inner shell 40. The groove 171 located inside the inner shell 40 is recessed from the inner surface of the inner shell 40 to the outside of the inner shell 40. The adjacent groove 172 is recessed from the outside surface of the inner shell 40 to the inside of the inner shell 40. There are washers 173 a, 173 b arranged in the grooves 171, 172. A flange 158 is arranged between the outer shell 30 and the lower bearing seat 57. A recession 1581, arranged between the flange 158 and the lower bearing seat 57, may accommodate the bending structure 170 at the bottom edge of the inner shell and the washers 173 a, 173 b. Applying the outer shell 30 and the upper bearing seat 56, the bending structure 70 located at the upper portion of the inner shell 40 and the washers 73 a, 73 b are tightly arranged in the recession 563. Applying the flange 158 and the lower bearing seat 57, the bending structure located at the lower portion of the inner shell 40 and the washers 173 a, 173 b are tightly arranged in the recession 1581. Consequently, multiple sealing effects are provided at the upper portion and the lower portion of the inner shell 40.

Again, please refer to FIG. 7. This embodiment is similar to FIG. 6. The difference is that the diameter of the bottom edge of the inner shell 140 is approximately larger than the outer diameter of the inner shell 140, such that the lower half section of the inner shell 140 has an inclining cone surface 141 that is narrow in upper side and wide in lower side. There is a wrinkling structure 142 shaped as waves on the inclining cone surface 141 in the axial direction. By such design of the inclining cone surface 141, it will facilitate the inner shell 140 in inserting into the outer shell 30. And, by this wrinkling structure 142, the heat generated from the eddy current during the running of the motor may be absorbed. Consequently, an appropriate tolerance of deformation may be provided to the inner shell 140.

In sum, the invention has following advantages:

-   -   1. The bending structure and the plural washers may form         multiple sealing effects, such that a superior function may be         reached;     -   2. Its structure is simple and easy to process, such that the         cost may be reduced;     -   3. The inner shell has detachability, such that its maintenance         is easy;     -   4. Its bearing seat is arranged on the outer shell with thicker         wall, such that the damage of the structure of the inner shell         may be avoided and its stability is secured.

However, above description is only the preferable embodiment of the present invention and can not be regarded as a restriction for its scope. That is, any variation and modification made according to the claimed field of the invention still possess its merits and are also within its spirit and field, so they are all regarded as further executing situations for the present invention. 

1. A canned motor-pump's structural improvement, which mainly has: an outer shell; and an inner shell, which is axially arranged in the said outer shell, and in which an axis and a motor's rotor are axially installed, and two sides of the axis are respectively arranged in an upper bearing and a lower bearing, and the two bearings are respectively arranged in a bearing seat, the bearing seat arranged at the upper portion of the axis is appropriately projected out the outer shell in axial direction and, by a fastening ring fastened to the projection section, the bearing seat is positioned at the upper portion of the outer shell; the inner shell has a bending structure, which is to form at least two grooves surrounding the inner shell, and the openings of the adjacent grooves are respectively faced the inner wall and the outer wall of the inner shell, and there are washers arranged in the grooves; stator and coil are arranged between the said outer shell and inner shell, and there is a seat arranged between the outer shell and the bottom of the inner shell; the inner shell is placed into the outer shell, and the upper edge of the inner shell is clapped between the upper bearing seat and the outer shell, and the bottom edge of the inner shell is welded to a seat for supporting the bearing seat of the bottom and, when the outer shell is bolted to the pump shell, the seat is insulated from the penetration of liquid by the sealing washers, and the axis is extended into the pump shell and axially arranged to impeller, such that a canned motor-pump's structure is constructed and, by the tight inter-abutments of bearing seats, bending structure, washers and outer shell, a sealing effect is achieved and the penetration of the liquid into the coil is indeed prevented.
 2. The canned motor-pump's structural improvements according to claim 1, the bending structure of the inner shell is arranged at the upper edge of the inner shell, wherein: the groove located inside the inner shell is recessed from the outer surface of the inner shell to the inside of the inner shell, and the adjacent groove is recessed from the inner surface of the inner shell to the outside of the inner shell, and an accommodation space is arranged between the outer shell and the bearing seat to accommodate the bending structure and the washers; by the outer shell and the bearing seat, the grooves and the washers of the inner shell are clapped in the accommodation space, and the outer wall of the groove located inside the inner shell is abutted with the bearing seat, and the washer arranged in the inside groove is abutted between the inner wall of the groove and the outer shell, and the adjacent outer wall of the groove located at the outside of the inner shell is abutted to the outer shell, and the washer arranged in the outside groove is abutted among the inner wall of the outside groove, the bearing and the outer shell, and a multiple sealing effect is thereby formed.
 3. The canned motor-pump's structural improvement according to claim 1, the bending structure is arranged at the upper edge and the bottom edge of the inner shell, wherein: for the bending structure arranged at the upper edge of the inner shell, the groove located at the inside of the inner shell is recessed from the outer surface of the inner shell into the inner shell, and the adjacent groove is recessed from the inner surface of the inner shell to the outside of the inner shell, and an accommodation space, arranged between the outer shell and the upper bearing seat, may accommodate the bending structure and the washers arranged at the upper edge of the inner shell; for the bending structure arranged at the bottom edge of the inner shell, the groove located at the inside of the inner shell is recessed from the inner surface of the inner shell to the outside of the inner shell, and adjacent groove is recessed from the outer surface of the inner shell into the inner shell, and there is a flange arranged between the outer shell and the lower bearing seat, and an accommodation space, arranged between the flange and the lower bearing, may accommodate the bending structure and the washers arranged at tile bottom edge of the inner shell; by the outer shell and the upper bearing seat, the grooves and the washers located at the upper portion of the inner shell are clapped in the accommodation space and, by the flange and the lower bearing seat, the grooves and the washers located at the lower portion of the inner shell are clapped in the accommodation space, and the upper portion and the bottom portion of the inner shell are all provided with multiple sealing effect.
 4. The canned motor-pump's structural improvement according to claim 3, wherein a wrinkling structure of wave's shape is axially arranged on the inner shell far away from the bending structures arranged at two sides of the inner shell, such that an appropriate tolerance is provided to the deformation of the inner shell.
 5. The canned motor-pump's structural improvement according to claim 1, wherein the diameter of the bottom edge of the inner shell is approximately larger than the outer distance of the inner shell, such that the inner shell has an inclining cone surface with narrow upper side and wide lower side.
 6. The canned motor-pump's structural improvement according to claim 5, wherein a wrinkling structure of wave's shape is axially arranged on the inclining cone surface, such that an appropriate tolerance is provided to the deformation of the inner shell.
 7. A canned motor's structural improvement, which mainly has: an outer shell; and an inner shell, which is axially arranged in the said outer shell, and in which an axis and a motor's rotor are axially installed, and two sides of the axis are respectively arranged in an upper bearing and a lower bearing, and the two bearings are respectively arranged in a bearing seat; stator and coil are arranged between the said outer shell and inner shell; the inner shell has a bending structure, which is to form at least two grooves surrounding the inner shell, and the openings of the adjacent grooves are respectively faced the inner wall and the outer wall of the inner shell, and there are washers arranged in the grooves; the inner shell is placed into the outer shell and is inset between the outer shell and the bearing seat; by the tight inter-abutments of bearing seats, bending structure, washers and outer shell, a sealing effect is achieved and the penetration of the liquid into the coil is indeed prevented.
 8. The canned motor's structural improvement according to claim 7, the bending structure is arranged at the upper edge of the inner shell, and the bottom edge of the inner shell is clapped and welded between the corresponding bearing seat and a seat arranged in the outer shell, wherein: the groove located inside the inner shell is recessed from the outer surface of the inner shell to the inside of the inner shell, and the adjacent groove is recessed from the inner surface of the inner shell to the outside of the inner shell, and an accommodation space is arranged between the outer shell and the bearing seat to accommodate the bending structure and the washers; by the outer shell and the bearing seat, the grooves and the washers of the inner shell are clapped in the accommodation space, and the outer wall of the groove located inside the inner shell is abutted with the bearing seat, and the washer arranged in the inside groove is abutted between the inner wall of the groove and the outer shell, and the adjacent outer wall of the groove located at the outside of the inner shell is abutted to the outer shell, and the washer arranged in the outside groove is abutted among the inner wall of the outside groove, the bearing and the outer shell, and a multiple sealing effect is thereby formed.
 9. The canned motor's structural improvement according to claim 7, the bending structure is arranged at the upper edge and the bottom edge of the inner shell, wherein: for the bending structure arranged at the upper edge of the inner shell, the groove located at the inside of the inner shell is recessed from the outer surface of the inner shell into the inner shell, and the adjacent groove is recessed from the inner surface of the inner shell to the outside of the inner shell, and an accommodation space, arranged between the outer shell and the upper bearing seat, may accommodate the bending structure and the washers arranged at the upper edge of the inner shell; for the bending structure arranged at the bottom edge of the inner shell, the groove located at the inside of the inner shell is recessed from the inner surface of the inner shell to the outside of the inner shell, and adjacent groove is recessed from the outer surface of the inner shell into the inner shell, and there is a flange arranged between the outer shell and the lower bearing seat, and an accommodation space, arranged between the flange and the lower bearing, may accommodate the bending structure and the washers arranged at the bottom edge of the inner shell; by the outer shell and the upper bearing seat, the grooves and the washers located at the upper portion of the inner shell are clapped in the accommodation space and, by the flange and the lower bearing seat, the grooves and the washers located at the lower portion of the inner shell are clapped in the accommodation space, and the upper portion and the bottom portion of the inner shell are all provided with multiple sealing effect.
 10. The canned motor's structural improvement according to claim 9, wherein a wrinkling structure of wave's shape is axially arranged on the inner shell far away from the bending structures arranged at two sides of the inner shell, such that an appropriate tolerance is provided to the deformation of the inner shell.
 11. The canned motor-pump's structural improvement according to claim 7, wherein the diameter of the bottom edge of the inner shell is approximately larger than the outer diameter of the inner shell, such that the inner shell has an inclining cone surface with narrow upper side and wide lower side.
 12. The canned motor's structural improvement according to claim 11, wherein a wrinkling structure of wave's shape is axially arranged on the inclining cone surface, such that an appropriate tolerance is provided to the deformation of the inner shell.
 13. The canned motor's structural improvement according to claim 7, wherein the bearing seat arranged at the upper portion of the axis is appropriately projected out the outer shell in axial direction and, by a fastening ring fastened to the projection section, the bearing seat is positioned at the upper portion or the outer shell.
 14. The canned motor-pump's structural improvement according to claim 3, wherein the diameter of the bottom edge of the inner shell is approximately larger than the outer distance of the inner shell, such that the inner shell has an inclining cone surface with narrow upper side and wide lower side.
 15. The canned motor-pump's structural improvement according to claim 9, wherein the diameter of the bottom edge of the inner shell is approximately larger than the outer diameter of the inner shell, such that the inner shell has an inclining cone surface with narrow upper side and wide lower side. 